<!DOCTYPE html>
<html>
  <head>
    <title>Tracer XHR Network Resource example</title>
  </head>
  <body>
    <div id="response-status"></div>
    <div id="response-body"></div>
    <script>
      async function performXHR() {
        const response = await window.fetch('./file.json', {method: 'POST', body: JSON.stringify({prop: 'value'})});
        document.querySelector('#response-status').innerText = response.status;
        const responseText = await response.text();
        document.querySelector('#response-body').innerText = responseText;
      }
    </script>
    <a onclick="javascipt:performXHR();">Download</a>
  </body>
</html>